Art of transmitting intelligence.



No. 734,476. PATENTED JULY 21, 1903. H. SHOEMAIKER.

ART OF TRANSMITTHTG INTELLIGENCE.

APPLIUATION FILED APR. 24, 1903.

If 1 .1. f fl L5 H0 MODEL.

UNITE STATES Patented July 21, 1903.

P TENT v OFFICE.

HARRY SI-IOEMAKER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR ONE- HALF TOMARIE V. GEHRING, F PHILADELPHIA, PENNSYLVANIA.

ART OF TRANSMITTING |I |TELI.,lG ENCE SPECIFlCATION forming part ofLetters Patent No. 734,476, dated July 2 1, 1903.

Original application filed January 8, 1903, Serial No, 138,228.v Dividedand this application filed April 24, 1903. Serial 7 v ITO-1543110- (Nomodel.) 1.

T0 otZZ whom it mag concern.

Be it known that I, HARRY SHOEMAKER, a

citizen of the United States, residingat Phila My invention relates towireless signaling 10 systems, more especially those in which the energyrepresenting the signal ormessage is of the electroradiant type andtransmitted through the natural media.

My invention relates more especially to the r 5 method of recordingmessages or signals at the receiving-stations.

My invention involves the principle that electromagnetic radiations havethe property by transformation into high-frequency oscilzo latorycurrents of changing the magnetism,

either sustained or permanent, of a magnetized mass, generally in thedirection of reducing the magnetization. 7

My invention consists in the method of dynamically generating therecording-impulse by the rapid relative movement of a magnetized masswith respect to a circuit, the arriving of electroradiationsbeingemployed to cause variations of magnetism in a rapidlymovingmagnetized mass.

It is a well-known fact that the permanent or residual magnetism of amass of iron, steel,

in an aerial conductor by electrical radiations. impinging upon saidconductor when placed in the vicinity of or surrounding a normallymagnetized mass will cause such mass toal- 4o ter its magnetizationgenerally in the direction of reducing suchmagnetization. It is thisprinciple which underlies my invention;

In my receiver I employ a rotating or moving mass of metal, which ismaintained in a magnetic condition by means of a magnet of unvaryingstrength. The portion of the mass which has passed such magnet ispermanently magnetized to a greater or less degree. Later in its travelthe magnetized mass comes under the influence of a winding in operativerelation with the receiving-conductor of a Wireless signaling system,and if electroradiant' energy is arriving the magnetism of that portionof the moving mass which is in the'immediate vicinity of such winding ischanged. The result is that different portions of the revolving mass aremagnetized at difierent intensities,and.in consequence when or steel orthe wire or ribbon is normally-magn'ctiz'ed to a certain intensity by amagnet,

and the effect of the electroradiant energy is to produce locally in themoving magnetized mass spots or portions, Whose magnetization is oflessdensitythan the normal-magnetization of the mass. This portionlessdensely magnetized coming then into the magnetized circuitsurrounded by a winding causes a change in'the line of force threadingsuch 8o magnetized circuit, and in consequence there is an inductiveaction in the winding surrounding such magnetic circuit, resulting in acurrentflow in such winding, suchcurrentfiow being utilized to produce asignal. If 85. the spots or portions of the magnetized mass which havebeen diminished in their intensity of magnetization are moved with greatrapidity past or through the magnetic circuit surrounded bya windingincluding a translat- 9o ing device, the inductive action on such-windingwill be verygreatindeed,becauseofthesuddennessor great-rate'change oflines of force threading such winding. By this means, even with slightdemagnetization due to the re- 5 ceived energy, I am enabled to producerelatively great effects in the receiver-translating device. In otherwords, by applying great speed to-the moving magnetized mass, which isuniformly magnetized, due to received electroradiant energy, I amperforming the equivalent of increasing the voltage of the inducedcurrent with a given strength of field. This process amounts todynamically generating strong impulses in the circuit ofa translatingdevice, the energy of such impulses being derived from the source ofpower driving the magnetized mass, but the amount of energy beingcontrolled also by the received electroradiant energy. This arrangementamounts to dynamically generating an electric current in the circuit ofthe translating device, and I style my receiver, in consequence, adynamic receiver. This arrangement differs distinctly from that whereinthe impulse in the circuit of the receiving device is due simply tostatic inductive effect (the static transformer efiects) where themotion of the magnetized mass is merely incidental to the impulse, butnot a producer or generator of it.

Reference is to be had to the accompanying drawings, in which- Figure 1shows in side elevation an arrangement in which the moving magnetizedmass is in the form of a wire or ribbon and a diagrammatic View of thearrangement of the aerial and receiver circuits in connection therewith.Fig. 2 is a plan view of Fig. 1 with the diagrammatic view of thecircuits omitted. Fig. 3 is a fragmentary view showing in diagram thearrangement of the essential parts and the circuits of the apparatusshown in Fig. 1. Fig. 4 is a fragmentary View showing in diagram thearrangement of circuits employed in conjunction with the modificationillustrated in Figs. 5, 6, and 7. Fig. 5 is a modified form of apparatusin which the magnetized mass comprises two concentric rings bridged bythe energizingmagnet, the aerial demagnetizing-circuit, and thereceiver-circuit. Fig. 6 is an end view of Fig. 5, partly in section,showing means of adjusting the several parts with respect to each other.Fig. 7 is a sectional View of the concentric magnetic masses supportedupon a common base-plate. Fig. 8 is a diagram matic View of a modifiedarrangement to be used in connection with the apparatus disclosed inFig. 1.

InFig. 1 is shown the dynamic receiver, Upon the base 1 are erected thestandards 2 2, in whose upper ends are mounted four pulleys 15, as seenin Fig. 2. The two pulleys at the right are mounted upon a shaft 4,supplied with a pulley 6, by means of which the shaft 4 is driven by anysuitable motor. The pulleys 15 at the left are each mounted upon anindependent shaft carried at the end of an arm 24. Over these pulleys 15are adapted to run the two wires or ribbons 16 16. These wires orribbons 16 are continuous iron or steel, the joint being carefullywelded and reduced to the same diameter as the remainder of the wire andfurther treated by annealing and the like, so that the magneticproperties of such joint shall be the same as the remainder of the wire.These wires 16 are stretched taut by means of the thumbnuts 25 engagingthe arm 24 by screw-threads. The pulley 6 is rotated at a Very high rateof speed by an external source of power, so that the wires 16 travel ata very high speed.

At 7 is shown a U-shaped magnet of the permanent type, immediately abovewhose poles pass the aforementioned wires 16 16. This causes then thewires 16 to be uniformly magnetized throughouttheir length.Thedisposition of this permanent magnet 7 is such that it is close tothe point where the wires 16 16 leave the pulleys 15 at the left. Thepurpose of this is to insure every portion of the wire as it passes apole to be at the same distance from such pole, so that themagnetization shall be uniform. If the magnet 7 were placed at a greaterdistance from the pulley 15 at the left, the wires 16, due to their highrate of speed, might shake and vibrate, so that the magnetization wouldnot be uniform. The direction of rotation of the pul- 'leys 15 is in acounter-clockwise direction, as

indicated by the arrow in Fig. 1.

22 is a supplemental base having a lug, through which extends theadjusting-screw 21 for the purpose of moving the member 20 backward andforward along the supplemental base 22 for the purpose of adjustment.

22 is a standard secured to the supplemental base 22 and carrying at itsupper end the two short helices 17 17, connected in series between theaerial conductorA and the earthplate E.

23 is an adjusting-screw by means of which this supplemental base may bemade to approach and recede from the permanent magnet 7. Upon the member20 is mounted the U-shaped permanent magnet 19, terminating in theupwardly-extending small cylindrical pole-pieces located in closeproximity to the wires 16 16 and surrounded by the coils 18.

26 26 are idlers which serve to steady the wires 16 where they pass overthe aforementioned poles in order that there will be no variation instrength of the magnet 19, due to any shaking or vibrating of said wires16 16.

By means of the supplemental base 22, the sliding member 20, and the twoadjustingscrews 23 and 21 it is possible to adjust the helices 17 withrespect to the permanent magnet 7 and also with respect to the magnet19.

The coils 18, surrounding the poles of magnet 19, are joined in serieswith each other and with the primary B of the transformer. The secondaryS of this transformer is joined in series with the adjustable inductanceL, telephone-receiver R, and condenser C.

The operation is as follows: Normally the wires 16 16 are traveling at arapid rate and are uniformly magnetized by the permanent magnet 7. Uponthe reception of electroradiant energy, however, through the agency ofhelices 17 the magnetism in the wires 16 immediately surrounded by saidhelices is changed, producing,in eifect,a spot or portion tinct from themagnetic circuit surrounded number of lines of force threading thecoils18 is varied and'changed, and in consequence there is induced in thecoils 18' and the circuit including them an impulse of current, which istransformed and flows through the telephone-receiver R, producing thesound or click. There is a sound or clickproduced for each train ofwavesemitted at the transmitting-station and received upon the aerialconductor A. e

Fig. 3 shows more clearly the disposition of the circuits employed inconnection with Fig. 1. In this arrangement it is to be noticed that theaerial winding is separate and disby a winding in which thesignal-producing impulse is to be induced. It is in virtue of thisarrangement that the important result is obtained of generatingdynamically, as distinct from statically, the impulse producing thesignal, and whereby the energy of such impulse maybe made great becauseof a transformation from mechanical energy supplied at pulley 6 intoelectrical energy in the circuit of the coils 18. The action is, infact, similar to that in a dynamo-electric generator, where thefield-magnet is rotated or moved with respect to the armature-coils. Theenergy generated in the armature-coils is, in fact, derived frommechanical energy, which moves the field-magnet and is dependent uponthe speed of such field-magnet and also upon the strength of such field.In the disposition shown in Fig. 1 the magnetized wires 16 correspond tothe moving field and the coils 18 correspond to the armature-winding.The energy generated in the coils 18 is similarly dependent upon therate of'change of the magnetism threading said coil. This rate of changeis made large by causing the wires 16 16 to travel at a high rate ofspeed, and upom this rate of speed is dependent the energy of theimpulse induced in said coils. As previously stated, there is an impulseinduced in the coils 18 for each train of Waves received at thereceiving-station. In consequence if these trains of waves succeed eachother uniformly at a definite rate there will be pro duced in the coils18 periodic currents of a rate equal to the rate of succession of thewave-trains, and similarly in the circuit of the telephone-receiver Bthere will be alternating or fluctuating currents of a frequencydepending upon the rate of succession of the transmitted wave-trains. Bysuitably adjusting the inductance Land the condenser O with respect tothe additional inductance of the secondary winding S and of the windingsof the receiver R these condary circuit may be attunedso that the saidcircuit will vin Fig. 1.

slect only those currents as controlled by wairje train's'succeeding'e'achother at a 'predetermined rate and representing apredetermined message transmitted from a predeter-.

mined station. A'variation in speed of the wires 16 16ifwill notinterfere with this selectivity, becaii'se at whatever speed these Wirestravel the same number of demagnetized spots orportiohs will pass thepoles of the magnet 19 in a unit of time. It is thus seen that nomessage will be recorded in receiver Rexcept that represented by thewave-trains succeeding each other at the proper rate, and any otherWave-trains of different rate of succession impinging upon the aerialconductor A will not produce a signal in the receiver R.

In Fig. 7 are showntwo concentric ironor steel rings 28 and 34, securedto the face of the disk'27, of non magn'etizable material. The disk 27is mounted upon the shaft 4, (shown in Fig. 5,) which is driven bypulley 6 and rotates on centers supported by the brackets 2 2, securedto the base 1. 7 is a U-' shaped magnet supported on the base 1 in suchmanner that the ring 28 will rotate past one of its poles while the ring34 rotates past the other of its poles. At 17 is shown a finelydividedor laminated member, of. magnetizable material, surrounded by a helixconnected in series between the aerial conductor A and the earth-plateE, asshown in Fig.4. This member 17 and itshelix are supported at theend of arm 33 in such manner that the ends of the magnetizable materialare oppo-' site the rings 28 and 34 inan arrangement similar to themagnet 7. By means of screw 30, extending through a projection of theright-hand bracket 2, the position of 17 with relation to the magnet 7may be adjusted. 19 is a U-shaped magnet Whose small cylin dricalpole-pieces are arranged opposite the rings 28 and 34, 18 representingcoils surrounding these pole-pieces. The magnet 19 and the coils 18 aresupported at the end of arm 32. By means of the thumb-screw 31' theposition of the magnet 19 and the coils 18 may be adjusted with respectto the member 17. This thumb-screw 31 extends through a bracket 29 on astandard 2.

is the same as that represented in Fig. 1, the

rings 28 and 34 corresponding with the wires Fig. 1,as well as Fig. 6,should be so wound and so connected that the currents induced in themwill not oppose each other, but will be cumulative in their effects.

In Fig. 8 the aerial conductor A, winding 17, and wires 16 are the sameas illustrated The coils 35, however, surround these wires or ribbons 16in place of the arrang'ement shown in Fig. 1,where the coils,

18are placed on a magnetic circuit in the vic'inityof the wire 16.ation, however, is the same in each case. Im-

In efiect this arrangement, as shown in Figs. 4, 5, 6, and 7,

Theprinciple of oper- &

pulses are generated in coils 35 and operate upon the receiver R toreproduce the signal.

Though I have shown the demagnetizing winding in each instance asconnected in series between an aerial conductor and earth, it is to beunderstood that such winding may be arranged in any other relation, asWell understood in this art. For example, such winding might be in thecircuit of the secondary of a transformer or in a closed tuned circuitfor the purpose of increasing a current component of the energytraversing such winding.

It is to be further understood that I do not limit my invention to theprecise arrangement herein disclosed, for many equivalent arrangementsare obvious to those skilled in the art.

This application is a division of my application filed January 8, 1903,Serial No. 138,228.

What I claim is- 1. The method of renderingintelligible electroradiantenergy transmitted through the natural media and representing a signalor message, which consists in changing the magnetism of a mass by saidelectroradiant energy, moving said mass with relation to a circuit, andgenerating in said circuit a signalproducing impulse in virtue of themotion of said mass with respect to said circuit.

2. The method of rendering intelligible electroradiant energytransmitted through the natural media and representing asignal ormessage, which consists in changing the magnetism of a mass by saidelectroradiant energy, moving said mass with relation to a circuit,generating a current in said circuit in virtue of the motion of saidmass, and producing a signal by said current.

3. The method of renderingintelligible electroradiant energy transmittedthrough the natural media and representing a signal or message, whichconsists in changing the magnetism of a mass by said electroradiantenergy efiects, moving said mass with relation to a circuit, generating.in said circuit electric currents in virtue of the motion of said mass,and selecting a current fluctuating at a rate characteristic of apredetermined signal 01' message, to reproduce said signal or message.

HARRY SHOEMAKER.

Witnesses:

J OHN THIEL, MAE HOFMANN.

